scholarly journals Methanol Promotes Atmospheric Methane Oxidation by Methanotrophic Cultures and Soils

1998 ◽  
Vol 64 (3) ◽  
pp. 1091-1098 ◽  
Author(s):  
J. Benstead ◽  
G. M. King ◽  
H. G. Williams
Keyword(s):  
Methane Oxidation ◽  
Standard Errors ◽  
Atmospheric Methane ◽  
Methylosinus Trichosporium ◽  
Methane Consumption ◽  
Air Supply ◽  
Chemostat Cultures ◽  
Methane Uptake ◽  
Kinetics Of

ABSTRACT Two methanotrophic bacteria, Methylobacter albus BG8 and Methylosinus trichosporium OB3b, oxidized atmospheric methane during batch growth on methanol. Methane consumption was rapidly and substantially diminished (95% over 9 days) when washed cell suspensions were incubated without methanol in the presence of atmospheric methane (1.7 ppm). Methanotrophic activity was stimulated after methanol (10 mM) but not methane (1,000 ppm) addition. M. albus BG8 grown in continuous culture for 80 days with methanol retained the ability to oxidize atmospheric methane and oxidized methane in a chemostat air supply. Methane oxidation during growth on methanol was not affected by methane deprivation. Differences in the kinetics of methane uptake (apparent Km andV max) were observed between batch- and chemostat-grown cultures. The V max and apparent Km values (means ± standard errors) for methanol-limited chemostat cultures were 133 ± 46 nmol of methane 108 cells−1 h−1and 916 ± 235 ppm of methane (1.2 μM), respectively. These values were significantly lower than those determined with batch-grown cultures (V max of 648 ± 195 nmol of methane 108 cells−1 h−1 and apparent Km of 5,025 ± 1,234 ppm of methane [6.3 μM]). Methane consumption by soils was stimulated by the addition of methanol. These results suggest that methanol or other nonmethane substrates may promote atmospheric methane oxidation in situ.

scholarly journals Effects of Ammonium and Non-Ammonium Salt Additions on Methane Oxidation by Methylosinus trichosporium OB3b and Maine Forest Soils

1998 ◽  
Vol 64 (1) ◽  
pp. 253-257 ◽  
Author(s):  
G. M. King ◽  
S. Schnell
Keyword(s):  
Soil Water Potential ◽  
Physiological Mechanism ◽  
Ammonium Salts ◽  
Atmospheric Methane ◽  
Exchange Reactions ◽  
Methylosinus Trichosporium Ob3b ◽  
Methylosinus Trichosporium ◽  
Methane Consumption ◽  
Pure Cultures ◽  
Methane Concentrations

ABSTRACT Additions of ammonium and non-ammonium salts inhibit atmospheric methane consumption by soil at salt concentrations that do not significantly affect the soil water potential. The response of soils to non-ammonium salts has previously raised questions about the mechanism of ammonium inhibition. Results presented here show that inhibition of methane consumption by non-ammonium salts can be explained in part by ion-exchange reactions: cations desorb ammonium, with the level of desorption varying as a function of both the cation and anion added; differential desorption results in differential inhibition levels. Differences in the extent of inhibition among ammonium salts can also be explained in part by the effects of anions on ammonium exchange. In contrast, only minimal effects of cations and anions are observed in liquid cultures of Methylosinus trichosporiumOB3b. The comparable level of inhibition by equinormal concentrations of NH4Cl and (NH4)2SO4and the insensitivity of salt inhibition to increasing methane concentrations (from 10 to 100 ppm) are of particular interest, since both of these patterns are in contrast to results for soils. The greater inhibition of methane consumption for NH4Cl than (NH4)2SO4 in soils can be attributed to increased ammonium adsorption by sulfate; increasing inhibition by non-ammonium salts with increasing methane concentrations can be attributed to desorbed ammonium and a physiological mechanism proposed previously for pure cultures.

The analysis of methods for measurement of methane oxidation in landfills

2003 ◽  
Vol 48 (4) ◽  
pp. 45-52 ◽  
Author(s):  
A. Nozhevnikova ◽  
M. Glagolev ◽  
V. Nekrasova ◽  
J. Einola ◽  
K. Sormunen ◽  
...  
Keyword(s):  
Methane Oxidation ◽  
Atmospheric Methane ◽  
Oxidation Activity ◽  
13C Isotope ◽  
Microbiological Methods ◽  
In Situ Conditions ◽  
Different Seasons ◽  
Minimal Deviation ◽  
Different Depths

Landfills and dumps are important sources of atmospheric methane. There is no generally accepted estimate of the influence of methane oxidation on landfill methane emissions. The present work aimed to analyse different methods for the investigation of methane emission and oxidation in methane-producing environments (wetlands, landfills, sludge checks), and to develop the precise procedure for the landfills. The combination of geochemical and microbiological methods to estimate and monitor the oxidation and emission of methane in landfills during different seasons is proposed. It includes the measurements, both on the surface and at different depths (up to 1 m) of landfill ground of the following parameters: (1) concentrations of methane, carbon dioxide and oxygen; (2) quantity of 13C isotope in gas samples; (3) methane-oxidation activity of landfill grounds assayed with two different methods: (a) in conditions of no moisture or substrate limitations, and (b) in conditions with a minimal deviation to in situ conditions; (4) the density of methanotrophic microbial population.

scholarly journals Termites Facilitate Methane Oxidation and Shape the Methanotrophic Community

2013 ◽  
Vol 79 (23) ◽  
pp. 7234-7240 ◽  
Author(s):  
Adrian Ho ◽  
Hans Erens ◽  
Basile Bazirake Mujinya ◽  
Pascal Boeckx ◽  
Geert Baert ◽  
...  
Keyword(s):  
Methane Oxidation ◽  
Type I ◽  
Atmospheric Methane ◽  
Nest Area ◽  
Active Nest ◽  
Content Type ◽  
Reference Soil ◽  
Methane Budget ◽  
Species Analysis

ABSTRACTTermite-derived methane contributes 3 to 4% to the total methane budget globally. Termites are not known to harbor methane-oxidizing microorganisms (methanotrophs). However, a considerable fraction of the methane produced can be consumed by methanotrophs that inhabit the mound material, yet the methanotroph ecology in these environments is virtually unknown. The potential for methane oxidation was determined using slurry incubations under conditions with high (12%) andin situ(∼0.004%) methane concentrations through a vertical profile of a termite (Macrotermes falciger) mound and a reference soil. Interestingly, the mound material showed higher methanotrophic activity. The methanotroph community structure was determined by means of apmoA-based diagnostic microarray. Although the methanotrophs in the mound were derived from populations in the reference soil, it appears that termite activity selected for a distinct community. Applying an indicator species analysis revealed that putative atmospheric methane oxidizers (high-indicator-value probes specific for the JR3 cluster) were indicative of the active nest area, whereas methanotrophs belonging to both type I and type II were indicative of the reference soil. We conclude that termites modify their environment, resulting in higher methane oxidation and selecting and/or enriching for a distinct methanotroph population.

scholarly journals Methane Monooxygenase Gene Transcripts as Quantitative Biomarkers of Methanotrophic Activity in Methylosinus trichosporium OB3b

2020 ◽  
Vol 86 (23) ◽  
Author(s):  
Egidio F. Tentori ◽  
Ruth E. Richardson
Keyword(s):  
Methane Oxidation ◽  
Methane Monooxygenase ◽  
Methane Emissions ◽  
Mrna Transcript ◽  
Methylosinus Trichosporium ◽  
Transcript Levels ◽  
Content Type ◽  
Oxidation Rates ◽  
Pure Cultures

ABSTRACT Methanotrophic microorganisms are characterized by their ability to oxidize methane. Globally they have a significant impact on methane emissions by attenuating net methane fluxes to the atmosphere in natural and engineered systems, though the populations are dynamic in their activity level in soils and waters. Methanotrophs oxidize methane using methane monooxygenase (MMO) enzymes, and selected subunit genes of the most common MMOs, specifically pmoA and mmoX, are used as biomarkers for the presence and abundance of populations of bacterial methanotrophs. The relative expression of these biomarker genes is dependent on copper-to-biomass ratios. Empirically derived quantitative relationships between methane oxidation biomarker transcript amounts and methanotrophic activity could facilitate determination of methane oxidation rates. In this study, pure cultures of a model type II methanotroph, Methylosinus trichosporium OB3b, were grown in hollow-fiber membrane bioreactors (HFMBR) under different steady-state methane oxidation conditions. Methanotroph biomass (DNA based) and methane oxidation biomarker mRNA transcript amounts were determined using quantitative PCR (qPCR) and reverse transcription-PCR (RT-qPCR), respectively. Under both copper-present and copper-limited conditions, per-cell pmoA mRNA transcript levels positively correlated with measured per-cell methane oxidation rates across 3 orders of magnitude. These correlations, if maintained across different methanotrophs, could prove valuable for inferring in situ oxidation rates of methanotrophs and understanding the dynamics of their impact on net methane emissions. IMPORTANCE Methanotrophs are naturally occurring microorganisms capable of oxidizing methane and have an impact on global net methane emissions. The genes pmoA and mmoX are used as biomarkers for bacterial methanotrophs. Quantitative relationships between transcript amounts of these genes and methane oxidation rates could facilitate estimation of methanotrophic activity. In this study, a strong correlation was observed between per-cell pmoA transcript levels and per-cell methane oxidation rates for pure cultures of the aerobic methanotroph M. trichosporium OB3b grown in bioreactors. If similar relationships exist across different methanotrophs, they could prove valuable for inferring in situ oxidation rates of methanotrophs and better understanding their impact on net methane emissions.

scholarly journals Members of the GenusMethylobacterAre Inferred To Account for the Majority of Aerobic Methane Oxidation in Oxic Soils from a Freshwater Wetland

mBio ◽  
2018 ◽  
Vol 9 (6) ◽  
Author(s):  
Garrett J. Smith ◽  
Jordan C. Angle ◽  
Lindsey M. Solden ◽  
Mikayla A. Borton ◽  
Timothy H. Morin ◽  
...  
Keyword(s):  
Greenhouse Gas ◽  
Methane Oxidation ◽  
Single Gene ◽  
Freshwater Wetland ◽  
Rrna Gene ◽  
Atmospheric Methane ◽  
Metabolic Diversity ◽  
Methanogenic Activity ◽  
Methane Consumption ◽  
Methane Fluxes

ABSTRACTMicrobial carbon degradation and methanogenesis in wetland soils generate a large proportion of atmospheric methane, a highly potent greenhouse gas. Despite their potential to mitigate greenhouse gas emissions, knowledge about methane-consuming methanotrophs is often limited to lower-resolution single-gene surveys that fail to capture the taxonomic and metabolic diversity of these microorganisms in soils. Here our objective was to use genome-enabled approaches to investigate methanotroph membership, distribution, andin situactivity across spatial and seasonal gradients in a freshwater wetland near Lake Erie. 16S rRNA gene analyses demonstrated that members of the methanotrophicMethylococcaleswere dominant, with the dominance largely driven by the relative abundance of four taxa, and enriched in oxic surface soils. Three methanotroph genomes from assembled soil metagenomes were assigned to the genusMethylobacterand represented the most abundant methanotrophs across the wetland. Paired metatranscriptomes confirmed that these Old Woman Creek (OWC)Methylobactermembers accounted for nearly all the aerobic methanotrophic activity across two seasons. In addition to having the capacity to couple methane oxidation to aerobic respiration, these new genomes encoded denitrification potential that may sustain energy generation in soils with lower dissolved oxygen concentrations. We further show thatMethylobactermembers that were closely related to the OWC members were present in many other high-methane-emitting freshwater and soil sites, suggesting that this lineage could participate in methane consumption in analogous ecosystems. This work contributes to the growing body of research suggesting thatMethylobactermay represent critical mediators of methane fluxes in freshwater saturated sediments and soils worldwide.IMPORTANCEHere we used soil metagenomics and metatranscriptomics to uncover novel members within the genusMethylobacter. We denote these closely related genomes as members of the lineage OWCMethylobacter. Despite the incredibly high microbial diversity in soils, here we present findings that unexpectedly showed that methane cycling was primarily mediated by a single genus for both methane production (“CandidatusMethanothrix paradoxum”) and methane consumption (OWCMethylobacter). Metatranscriptomic analyses revealed that decreased methanotrophic activity rather than increased methanogenic activity possibly contributed to the greater methane emissions that we had previously observed in summer months, findings important for biogeochemical methane models. Although members of thisMethylococcalesorder have been cultivated for decades, multi-omic approaches continue to illuminate the methanotroph phylogenetic and metabolic diversity harbored in terrestrial and marine ecosystems.

scholarly journals Atmospheric methane removal: a research agenda

2021 ◽  
Vol 379 (2210) ◽  
pp. 20200454 ◽  
Author(s):  
Robert B. Jackson ◽  
Sam Abernethy ◽  
Josep G. Canadell ◽  
Matteo Cargnello ◽  
Steven J. Davis ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Methane Oxidation ◽  
Research Agenda ◽  
The Arctic ◽  
Anthropogenic Emissions ◽  
Atmospheric Methane ◽  
Model Intercomparison ◽  
Intercomparison Project ◽  
Removal Model

Atmospheric methane removal (e.g. in situ methane oxidation to carbon dioxide) may be needed to offset continued methane release and limit the global warming contribution of this potent greenhouse gas. Because mitigating most anthropogenic emissions of methane is uncertain this century, and sudden methane releases from the Arctic or elsewhere cannot be excluded, technologies for methane removal or oxidation may be required. Carbon dioxide removal has an increasingly well-established research agenda and technological foundation. No similar framework exists for methane removal. We believe that a research agenda for negative methane emissions—‘removal' or atmospheric methane oxidation—is needed. We outline some considerations for such an agenda here, including a proposed Methane Removal Model Intercomparison Project (MR-MIP). This article is part of a discussion meeting issue 'Rising methane: is warming feeding warming? (part 1)'.

In Situ Quantification of Atmospheric Methane Oxidation in Near-Surface Soils

2010 ◽  
Vol 9 (4) ◽  
pp. 1052-1062 ◽  
Author(s):  
Philipp A. Nauer ◽  
Martin H. Schroth
Keyword(s):  
Methane Oxidation ◽  
Atmospheric Methane ◽  
Surface Soils ◽  
Near Surface

scholarly journals Methanol Improves Methane Uptake in Starved Methanotrophic Microorganisms

1998 ◽  
Vol 64 (3) ◽  
pp. 1143-1146 ◽  
Author(s):  
Sigmund Jensen ◽  
Anders Priemé ◽  
Lars Bakken
Keyword(s):  
Forest Soil ◽  
Methane Oxidation ◽  
Atmospheric Methane ◽  
Free Atmosphere ◽  
Enrichment Cultures ◽  
Methane Uptake ◽  
Indigenous Forest ◽  
Immediate Response

ABSTRACT Methanotrophs in enrichment cultures grew and sustained atmospheric methane oxidation when supplied with methanol. If they were not supplied with methanol or formate, their atmospheric methane oxidation came to a halt, but it was restored within hours in response to methanol or formate. Indigenous forest soil methanotrophs were also dependent on a supply of methanol upon reduced methane access but only when exposed to a methane-free atmosphere. Their immediate response to each methanol addition, however, was to shut down the oxidation of atmospheric methane and to reactivate atmospheric methane oxidation as the methanol was depleted.

In situ study of electron beam-induced chemical vapor deposition of Au in an environmental TEM

1995 ◽  
Vol 53 ◽  
pp. 256-257
Author(s):  
J. Drucker ◽  
R. Sharma ◽  
J. Kouvetakis ◽  
K.H.J. Weiss
Keyword(s):  
Electron Beam ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Quantum Effect ◽  
Line Drawing ◽  
Chemical Vapor ◽  
Environmental Cell ◽  
Engineering Changes ◽  
Kinetics Of

Patterning of metals is a key element in the fabrication of integrated microelectronics. For circuit repair and engineering changes constructive lithography, writing techniques, based on electron, ion or photon beam-induced decomposition of precursor molecule and its deposition on top of a structure have gained wide acceptance Recently, scanning probe techniques have been used for line drawing and wire growth of W on a silicon substrate for quantum effect devices. The kinetics of electron beam induced W deposition from WF6 gas has been studied by adsorbing the gas on SiO2 surface and measuring the growth in a TEM for various exposure times. Our environmental cell allows us to control not only electron exposure time but also the gas pressure flow and the temperature. We have studied the growth kinetics of Au Chemical vapor deposition (CVD), in situ, at different temperatures with/without the electron beam on highly clean Si surfaces in an environmental cell fitted inside a TEM column.

In situ observation of the martensitic transformation in (Mg,Y)-PSZ

1986 ◽  
Vol 44 ◽  
pp. 500-501
Author(s):  
R-R. Lee
Keyword(s):  
Martensitic Transformation ◽  
High Strength ◽  
Nucleation And Growth ◽  
In Situ Observation ◽  
Considerable Potential ◽  
Transmission Electron ◽  
Structural Applications ◽  
Applied Stresses ◽  
Kinetics Of

Partially-stabilized ZrO2 (PSZ) ceramics have considerable potential for advanced structural applications because of their high strength and toughness. These properties derive from small tetragonal ZrO2 (t-ZrO2) precipitates in a cubic (c) ZrO2 matrix, which transform martensitically to monoclinic (m) symmetry under applied stresses. The kinetics of the martensitic transformation is believed to be nucleation controlled and the nucleation is always stress induced. In situ observation of the martensitic transformation using transmission electron microscopy provides considerable information about the nucleation and growth aspects of the transformation.

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